custom css fonts for buttons | or call to action

Hi Circle Friends 

I am working on a site for a client and I have added some custom fonts which are working great. I am looking to add that same font to the call to action buttons. I know there is a way to do. Can someone assist with this code?

I have looked and looked and have not had much luck. I am hoping that someone could assist me with this. 

Thanks in advanced

Different to help without url/template name.

Can you share link to your site?